1. Technical Field
This invention relates to nanoparticulates, microparticulates, films and other shaped polymer drug delivery systems. More particularly, this invention relates to biodegradable materials, capable of carrying a bioactive agent, comprising a polymer matrix and an enzyme capable of degrading the polymer matrix to release or aid in the release of the bioactive agent from the polymer matrix.
2. Related Art
Biodegradable polymers with a wide range of physical properties and lifetimes have been proposed for a variety of delivery vehicles for various bioactive agents such as drugs, nutraceuticals, growth factors, genes, and other products of biotechnology. Such polymers have a drug encapsulated in a polymeric matrix formulation for the subsequent sustained release of the drug.
Additionally, attaching enzymes to polymer matrices has been explored as a method to endow materials with unique functional attributes. For example, by plasma induced graft copolymerization of acrylic acid, glucose oxidase was conjugated to materials such as polyethylene in order to measure free glucose concentrations in solution. Various oxidative enzymes, such as horseradish peroxidase, glucose oxidase, and lactate oxidase have been incorporated into polyacrylamide-based redox polymers and evaluated for detection of analytes (including glucose and lactate) by “wiring” the enzyme to the redox polymer.
Further, there has been extensive work performed by others to increase enzyme solubility in organic solvents. Solubilization of enzymes in organic media has been primarily for the purpose of performing biocatalysis in homogeneous reaction media. One mechanism by which proteins from an aqueous phase were transferred to the organic phase is by using ionic surfactants. Interactions occur between the surface charges of proteins and the charged head-group of surfactants creating hydrophobic protein-surfactant complexes that can be extracted into organic media. Enzymes containing polymeric coatings, films and plastics have already been synthesized by hydrophobic ion-pairing.
Accordingly, there is always a need for an improved carrier material that can provide increased control of degradation rate for materials. It is to this need, among others, that this invention is directed.